Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep?
T/QRS ratio monitoring is used to help identify fetal asphyxia. However, immature animals have greater capacity to maintain blood pressure during severe asphyxia, raising the possibility that they may show an attenuated T/QRS increase during asphyxia. Chronically instrumented fetal sheep at 0.6 of g...
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| Format: | Article |
| Language: | English |
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Wiley
2014-01-01
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| Series: | Obstetrics and Gynecology International |
| Online Access: | http://dx.doi.org/10.1155/2014/314159 |
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| author | Guido Wassink Robert Galinsky Paul P. Drury Eleanor R. Gunn Laura Bennet Alistair J. Gunn |
| author_facet | Guido Wassink Robert Galinsky Paul P. Drury Eleanor R. Gunn Laura Bennet Alistair J. Gunn |
| author_sort | Guido Wassink |
| collection | DOAJ |
| description | T/QRS ratio monitoring is used to help identify fetal asphyxia. However, immature animals have greater capacity to maintain blood pressure during severe asphyxia, raising the possibility that they may show an attenuated T/QRS increase during asphyxia. Chronically instrumented fetal sheep at 0.6 of gestation (0.6 GA; n = 12), 0.7 GA (n = 12), and 0.8 GA (n = 8) underwent complete umbilical cord occlusion for 30 min, 25 min, or 15 min, respectively. Cord occlusion was associated with progressive metabolic acidosis and initial hypertension followed by severe hypotension, with a more rapid fall in mean arterial blood pressure (MAP) and carotid blood flow (CaBF) with advancing gestation. T/QRS ratio rose after occlusion more rapidly at 0.8 GA than in immature fetuses, to a similar final peak at all ages, followed by a progressive fall that was slower at 0.8 GA than in the immature fetuses. The increase in T/QRS ratio correlated with initial hypertension at 0.8 GA (P<0.05, R2 = 0.38), and conversely, its fall correlated closely with falling MAP in all gestational groups (P<0.01, R2 = 0.67). In conclusion, elevation of the T/QRS ratio is an index of onset of severe asphyxia in the last third of gestation, but not of fetal compromise. |
| format | Article |
| id | doaj-art-0a7f3ebc85094161a7582a85b9a8495e |
| institution | Kabale University |
| issn | 1687-9589 1687-9597 |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Wiley |
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| series | Obstetrics and Gynecology International |
| spelling | doaj-art-0a7f3ebc85094161a7582a85b9a8495e2025-02-03T06:01:48ZengWileyObstetrics and Gynecology International1687-95891687-95972014-01-01201410.1155/2014/314159314159Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep?Guido Wassink0Robert Galinsky1Paul P. Drury2Eleanor R. Gunn3Laura Bennet4Alistair J. Gunn5Fetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandFetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandFetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandFetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandFetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandFetal Physiology and Neuroscience Group, Department of Physiology, University of Auckland, Auckland 1023, New ZealandT/QRS ratio monitoring is used to help identify fetal asphyxia. However, immature animals have greater capacity to maintain blood pressure during severe asphyxia, raising the possibility that they may show an attenuated T/QRS increase during asphyxia. Chronically instrumented fetal sheep at 0.6 of gestation (0.6 GA; n = 12), 0.7 GA (n = 12), and 0.8 GA (n = 8) underwent complete umbilical cord occlusion for 30 min, 25 min, or 15 min, respectively. Cord occlusion was associated with progressive metabolic acidosis and initial hypertension followed by severe hypotension, with a more rapid fall in mean arterial blood pressure (MAP) and carotid blood flow (CaBF) with advancing gestation. T/QRS ratio rose after occlusion more rapidly at 0.8 GA than in immature fetuses, to a similar final peak at all ages, followed by a progressive fall that was slower at 0.8 GA than in the immature fetuses. The increase in T/QRS ratio correlated with initial hypertension at 0.8 GA (P<0.05, R2 = 0.38), and conversely, its fall correlated closely with falling MAP in all gestational groups (P<0.01, R2 = 0.67). In conclusion, elevation of the T/QRS ratio is an index of onset of severe asphyxia in the last third of gestation, but not of fetal compromise.http://dx.doi.org/10.1155/2014/314159 |
| spellingShingle | Guido Wassink Robert Galinsky Paul P. Drury Eleanor R. Gunn Laura Bennet Alistair J. Gunn Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? Obstetrics and Gynecology International |
| title | Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? |
| title_full | Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? |
| title_fullStr | Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? |
| title_full_unstemmed | Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? |
| title_short | Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep? |
| title_sort | does maturity affect cephalic perfusion and t qrs ratio during prolonged umbilical cord occlusion in fetal sheep |
| url | http://dx.doi.org/10.1155/2014/314159 |
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